Tony Blair lost his cool and refused to ever talk about his relationship with Rupert Murdoch's ex-wife, Wendi Deng, during a recent interview.

Blair hit the headlines last year after the media mogul divorced Deng, amid allegations his wife had an affair with the former prime minister.

When questioned on the topic by The Economist, Blair became so unnerved that he banged his coffee cup "so loudly into its saucer that it spilled and everyone in the room jumped".

He then reportedly broke out in a sweat when probed whether he had been "careless about his reputation".

Blair told the magazine the relationship is "not something I will ever talk about – I haven't and I won't".

The report then continued: "But did he find himself in a tangle over his friendship with Ms Deng? A large, dark pool of sweat has suddenly appeared under his armpit, spreading across an expensive blue shirt."

Leaked passages from Deng's diary said she had "warm feelings" for Blair which were compared to a "crush". The diary entries allegedly refer to Blair staying at the Murdochs' California ranch in October 2012 and April 2013, while Rupert Murdoch was abroad.

She was even said to have praised Blair's "good body", his "really, really good legs" and even his "butt", according to a report in Vanity Fair.

In 2013, a spokesman for Blair issued a statement saying: "If you are asking if they are having an affair, the answer is no."

Murdoch said this year he was "shocked" by the claims about Deng and Blair, and filed for divorce a week after staff at the ranch told him of their suspicions. The couple had been married for 14 years.

"Well, you know, everybody was talking about these things and never telling me anything... But then I was told two pretty circumstantial things about the ranch [where Deng had been staying]," Murdoch said in a Forbes magazine interview.

"I was in Australia. When I got back, I naturally asked the staff, and it opened up. That's the story. And then, you know, a week later I filed. As soon as I could find a lawyer."

Blair's close friends reportedly said the saga damaged him, especially financially, as Murdoch stopped contributing to Blair's charitable foundation and cut him off from other friendly donors in America.